Cranial nerves

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Cranial nerves

Cranial nerves are nerve

Nerve

A nerve is an enclosed, cable-like bundle of Peripheral nervous system axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons....
s that emerge directly from the brain stem

Brain stem

The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. The brain stem provides the main motor and sensory innervation to the face and neck via the cranial nerves....
in contrast to spinal nerve

Spinal nerve

The term spinal nerve generally refers to the mixed spinal nerve, which is formed from the dorsal and ventral roots that come out of the spinal cord....
s which emerge from segments of the spinal cord

Spinal cord

The spinal cord is a long, thin, tubular bundle of neuron and glia that extends from the brain. The brain and spinal cord together make up the central nervous system....
. Although thirteen cranial nerves in humans

Human anatomy

Human anatomy, which, with physiology and biochemistry, is a complementary basic medical science is primarily the scientific study of the morphology of the adult human body....
fit this description, twelve are conventionally recognized. The nerves from the third onward arise from the brain stem

Brain stem

Motor system

The motor system is the part of the peripheral nervous system that is involved to movement. It consists of the Corticospinal tract and extrapyramidal system....
and sensory

Sensory system

A sensory system is a part of the nervous system responsible for processing sense information. A sensory system consists of sensory receptors, neural pathways, and parts of the brain involved in sensory perception....
systems of the head and neck

Head and neck anatomy

Head and neck anatomy focuses on the structures of the head and neck of the human body, including the brain, bones, muscles, blood vessels, nerves, glands, nose, mouth, teeth, tongue, and throat....
region. However, unlike peripheral nerves which are separated to achieve segmental innervation

Segmental innervation

Segmental innervation refers to the distribution of nerves within an organ or muscle. These nerves are attached to a segment of the spine.Segmental innervation can be mapped through stimulation of the nerve at the spinal segment....
, cranial nerves are divided to serve one or a few specific functions in wider anatomical territories.

0

Cranial nerve zero

The terminal nerve, or cranial nerve zero, was discovered by German scientist Gustav Fritsch in 1878 in the brains of sharks. It was first found in humans in 1913, although its presence in humans remains controversial....
(CN0 is not traditionally recognized.)

Sensory

olfactory trigone

Olfactory trigone

The olfactory trigone is a small triangular area in front of the anterior perforated substance.Its apex, directed forward, occupies the posterior part of the olfactory sulcus, and is brought into view by throwing back the olfactory tract....
, medial olfactory gyrus, and lamina terminalis

Lamina terminalis

The median portion of the wall of the fore-brain vesicle consists of a thin lamina, the lamina terminalis, which stretches from the interventricular foramen to the recess at the base of the optic stalk....

New research indicates CN0 may play a role in the detection of pheromones >- | I

Olfactory nerve

The olfactory nerve, or cranial nerve I, is the first of twelve cranial nerves. The specialized olfactory receptor neurons of the olfactory nerve are located in the olfactory mucosa of the upper parts of the nasal cavity....

Sensory

Anterior olfactory nucleus

The anterior olfactory nucleus is a portion of the forebrain of vertebrates....

Transmits the sense of smell; Located in olfactory foramina

Olfactory foramina

The olfactory foramina are holes in the cribriform plate which transmit the olfactory nerves....
of ethmoid |- | II

Optic nerve

The optic nerve, also called cranial nerve II, transmits visual information from the retina to the brain....

Sensory

Lateral geniculate nucleus

The lateral geniculate nucleus is the primary processing center for Visual perception information received from the retina of the eye. The LGN is found inside the thalamus of the brain, and is thus part of the central nervous system....

Transmits visual information to the brain; Located in optic canal |- | III

Oculomotor nerve

The oculomotor nerve is the third of twelve paired cranial nerves. It controls most of the eye's movements, constriction of the pupil, and maintains an open eyelid....

Motor

Midbrain

Oculomotor nucleus

The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle....
, Edinger-Westphal nucleus

Edinger-Westphal nucleus

The Edinger-Westphal nucleus is the accessory parasympathetic nervous system cranial nerve nucleus of the oculomotor nerve , supplying the constricting muscles of the Iris ....

Innervates levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique, which collectively perform most eye movements; Located in superior orbital fissure

Superior orbital fissure

The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the Small wings of the sphenoid and Great wings of the sphenoid of the sphenoid bone....
|- | IV

Trochlear nerve

The trochlear nerve is a motor nerve that innervates a single muscle: the superior oblique muscle of the eye. An older name is pathetic nerve, which refers to the dejected appearance that is characteristic of patients with fourth nerve palsies....

Motor

Midbrain

Trochlear nucleus

The nucleus of the trochlear nerve is located in the midbrain, at the level of the inferior colliculus. It is a motor nucleus, so located near the midline....

Innervates the superior oblique muscle

Superior oblique muscle

For the abdominal muscle see: External oblique muscleThe superior oblique muscle, or obliquus oculi superior, is a fusiform muscle in the upper, medial side of the orbit whose primary action is intorsion and whose secondary actions are to abduction and Depression the eyeball ....
, which depresses, rotates laterally (around the optic axis), and intorts the eyeball; Located in superior orbital fissure

Superior orbital fissure

Trigeminal nerve

The trigeminal nerve is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system....

Both

Pons

The pons is a structure located on the brain stem. It is cranial to the medulla oblongata, caudal to the midbrain, and ventral to the cerebellum....

Principal sensory trigeminal nucleus, Spinal trigeminal nucleus

Spinal trigeminal nucleus

The spinal trigeminal nucleus is a Nucleus in the medulla oblongata that receives information about deep/crude touch, Pain and nociception, and temperature from the ipsilateral face....
, Mesencephalic trigeminal nucleus, Trigeminal motor nucleus

Trigeminal motor nucleus

The trigeminal motor nucleus contains motor neurons that innervate muscles of the first branchial arch, namely the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid muscle, and anterior belly of the digastric....

Receives sensation from the face and innervates the muscles of mastication

Muscles of mastication

Mastication is accomplished through the activity of the four muscles of mastication....
; Located in superior orbital fissure

Superior orbital fissure

Foramen rotundum

The foramen rotundum is a circular hole in the sphenoid bone that connects the middle cranial fossa and the pterygopalatine fossa....
(maxillary branch), and foramen ovale

Foramen ovale

There are multiple structures in the human body with the name foramen ovale :* In the fetal heart, the foramen ovale is a shunt from the right to left Atrium ....
(mandibular branch) |- | VI

Abducens nerve

Motor

Posterior margin of Pons

Pons

The pons is a structure located on the brain stem. It is cranial to the medulla oblongata, caudal to the midbrain, and ventral to the cerebellum....

Abducens nucleus

The abducens nucleus is the originating nucleus from which the abducens nerve emerges - a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the Anatomical terms of location portion of the pons, Anatomical terms of location to the sulcus limitans....

Innervates the lateral rectus, which abducts the eye; Located in superior orbital fissure

Superior orbital fissure

Facial nerve

The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla oblongata, and controls the muscles of facial expression, and taste to the anterior two-thirds of the tongue....

Both

Pons

The pons is a structure located on the brain stem. It is cranial to the medulla oblongata, caudal to the midbrain, and ventral to the cerebellum....
(cerebellopontine angle) above olive

Facial nucleus, Solitary nucleus

Solitary nucleus

The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial nerve , glossopharyngeal nerve and vagus nerve cranial nerves....
, Superior salivary nucleus

Superior salivary nucleus

The Superior salivary nucleus of the facial nerve is a visceromotor cranial nerve nucleus located in the pontine tegmentum.Parasympathetic efferent fibers of the facial nerve arise according to some authors from the small cells of the facial nucleus, or according to others from a special nucleus of cells scattered in the reticular formati...

Provides motor innervation to the muscles of facial expression and stapedius

Stapedius

The stapedius is the smallest skeletal muscle in the human body. At just over one millimeter in length, its purpose is to stabilize the smallest bone in the body, the stapes....
, receives the special sense of taste from the anterior 2/3 of the tongue, and provides secretomotor

Secretomotor

Secretomotor refers to the capacity of a structure to induce a gland to secrete a substance .Secretomotor nerve endings are frequently contrasted with sensory neuron endings and motor nerve endings....
innervation to the salivary gland

Salivary gland

The salivary glands in mammals are exocrine glands that produce saliva. They also secrete amylase, an enzyme that breaks down starch into glucose. In other organisms such as Insecta, salivary glands are often used to produce biologically important proteins like silk or glues, and fly salivary glands contain polytene chromosomes that have been usefu...
s (except parotid) and the lacrimal gland

Lacrimal gland

The lacrimal glands are paired almond-shaped glands, one for each eye, that secrete the aqueous layer of the tears film. They are situated in the upper, outer portion of each Orbit ....
; Located and runs through internal acoustic canal to facial canal

Facial canal

The facial canal is a canal running from the internal acoustic meatus to the stylomastoid foramen, with approximately 3cm total length is the longest osseous canal of a nerve in a man ....
and exits at stylomastoid foramen

Stylomastoid foramen

Between the styloid process and mastoid portion of the temporal bone processes of the temporal bone is the stylomastoid foramenIt is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery....
|- | VIII

Vestibulocochlear nerve

The vestibulocochlear nerve is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium information from the inner ear to the brain....
(or auditory-vestibular nerve or statoacustic nerve)

Sensory

Lateral to CN VII (cerebellopontine angle)

Vestibular nuclei

The vestibular nuclei are the cranial nuclei for the vestibular nerve....
, Cochlear nuclei

Cochlear nuclei

The cochlear nuclei consist of:* the dorsal cochlear nucleus, corresponding to the tuberculum acusticum on the dorso-lateral surface of the inferior peduncle; and...

Senses sound, rotation and gravity (essential for balance & movement); Located in internal acoustic canal |- | IX

Glossopharyngeal nerve

The glossopharyngeal nerve is the ninth of twelve pairs of cranial nerves . It exits the brainstem out from the sides of the upper Medulla oblongata, just rostral to the vagus nerve....

Both

Medulla

Medulla refers to the middle of something, and derives from the Latin word for 'marrow' .In medicine it refers to either bone marrow, the spinal cord, or more generally, the middle part of a structure ....

Nucleus ambiguus

The nucleus ambiguus is a region of histology disparate cell s located just Dorsum to the inferior olivary nucleus in the Human anatomical terms#Anatomical directions portion of the upper medulla oblongata....
, Inferior salivary nucleus, Solitary nucleus

Solitary nucleus

Receives taste from the posterior 1/3 of the tongue, provides secretomotor innervation to the parotid gland

Parotid gland

For the toad wart, see parotoid gland.The parotid gland is the largest of the salivary glands. It is found wrapped around the mandibular ramus, and it secretes saliva through Stensen's duct into the oral cavity, to facilitate mastication and swallowing....
, and provides motor innervation to the stylopharyngeus (essential for tactile, pain, and thermal sensation).

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Encyclopedia

Cranial nerves are nerve

Nerve

Brain stem

Spinal nerve

Spinal cord

Human anatomy

Brain stem

Motor system

The motor system is the part of the peripheral nervous system that is involved to movement. It consists of the Corticospinal tract and extrapyramidal system....
and sensory

Sensory system

Head and neck anatomy

Segmental innervation

#	Name	Sensory Motor or Both	Origin	Nuclei	Function >- \| 0	Cranial nerve zero Cranial nerve zero The terminal nerve, or cranial nerve zero, was discovered by German scientist Gustav Fritsch in 1878 in the brains of sharks. It was first found in humans in 1913, although its presence in humans remains controversial.... (CN0 is not traditionally recognized.)	Sensory		olfactory trigone Olfactory trigone The olfactory trigone is a small triangular area in front of the anterior perforated substance.Its apex, directed forward, occupies the posterior part of the olfactory sulcus, and is brought into view by throwing back the olfactory tract.... , medial olfactory gyrus, and lamina terminalis Lamina terminalis The median portion of the wall of the fore-brain vesicle consists of a thin lamina, the lamina terminalis, which stretches from the interventricular foramen to the recess at the base of the optic stalk....	New research indicates CN0 may play a role in the detection of pheromones >- \| I	Olfactory nerve Olfactory nerve The olfactory nerve, or cranial nerve I, is the first of twelve cranial nerves. The specialized olfactory receptor neurons of the olfactory nerve are located in the olfactory mucosa of the upper parts of the nasal cavity....	Sensory		Anterior olfactory nucleus Anterior olfactory nucleus The anterior olfactory nucleus is a portion of the forebrain of vertebrates....	Transmits the sense of smell; Located in olfactory foramina Olfactory foramina The olfactory foramina are holes in the cribriform plate which transmit the olfactory nerves.... of ethmoid \|- \| II	Optic nerve Optic nerve The optic nerve, also called cranial nerve II, transmits visual information from the retina to the brain....	Sensory		Lateral geniculate nucleus Lateral geniculate nucleus The lateral geniculate nucleus is the primary processing center for Visual perception information received from the retina of the eye. The LGN is found inside the thalamus of the brain, and is thus part of the central nervous system....	Transmits visual information to the brain; Located in optic canal \|- \| III	Oculomotor nerve Oculomotor nerve The oculomotor nerve is the third of twelve paired cranial nerves. It controls most of the eye's movements, constriction of the pupil, and maintains an open eyelid....	Motor	Midbrain	Oculomotor nucleus Oculomotor nucleus The fibers of the oculomotor nerve arise from a nucleus in the midbrain, which lies in the gray substance of the floor of the cerebral aqueduct and extends in front of the aqueduct for a short distance into the floor of the third ventricle.... , Edinger-Westphal nucleus Edinger-Westphal nucleus The Edinger-Westphal nucleus is the accessory parasympathetic nervous system cranial nerve nucleus of the oculomotor nerve , supplying the constricting muscles of the Iris ....	Innervates levator palpebrae superioris, superior rectus, medial rectus, inferior rectus, and inferior oblique, which collectively perform most eye movements; Located in superior orbital fissure Superior orbital fissure The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the Small wings of the sphenoid and Great wings of the sphenoid of the sphenoid bone.... \|- \| IV	Trochlear nerve Trochlear nerve The trochlear nerve is a motor nerve that innervates a single muscle: the superior oblique muscle of the eye. An older name is pathetic nerve, which refers to the dejected appearance that is characteristic of patients with fourth nerve palsies....	Motor	Midbrain	Trochlear nucleus Trochlear nucleus The nucleus of the trochlear nerve is located in the midbrain, at the level of the inferior colliculus. It is a motor nucleus, so located near the midline....	Innervates the superior oblique muscle Superior oblique muscle For the abdominal muscle see: External oblique muscleThe superior oblique muscle, or obliquus oculi superior, is a fusiform muscle in the upper, medial side of the orbit whose primary action is intorsion and whose secondary actions are to abduction and Depression the eyeball .... , which depresses, rotates laterally (around the optic axis), and intorts the eyeball; Located in superior orbital fissure Superior orbital fissure The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the Small wings of the sphenoid and Great wings of the sphenoid of the sphenoid bone....
Trigeminal nerve Trigeminal nerve The trigeminal nerve is responsible for sensation in the face. Sensory information from the face and body is processed by parallel pathways in the central nervous system....	Both	Pons Pons The pons is a structure located on the brain stem. It is cranial to the medulla oblongata, caudal to the midbrain, and ventral to the cerebellum....	Principal sensory trigeminal nucleus, Spinal trigeminal nucleus Spinal trigeminal nucleus The spinal trigeminal nucleus is a Nucleus in the medulla oblongata that receives information about deep/crude touch, Pain and nociception, and temperature from the ipsilateral face.... , Mesencephalic trigeminal nucleus, Trigeminal motor nucleus Trigeminal motor nucleus The trigeminal motor nucleus contains motor neurons that innervate muscles of the first branchial arch, namely the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid muscle, and anterior belly of the digastric....	Receives sensation from the face and innervates the muscles of mastication Muscles of mastication Mastication is accomplished through the activity of the four muscles of mastication.... ; Located in superior orbital fissure Superior orbital fissure The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the Small wings of the sphenoid and Great wings of the sphenoid of the sphenoid bone.... (ophthalmic branch), foramen rotundum Foramen rotundum The foramen rotundum is a circular hole in the sphenoid bone that connects the middle cranial fossa and the pterygopalatine fossa.... (maxillary branch), and foramen ovale Foramen ovale There are multiple structures in the human body with the name foramen ovale :* In the fetal heart, the foramen ovale is a shunt from the right to left Atrium .... (mandibular branch) \|- \| VI	Abducens nerve	Motor	Posterior margin of Pons Pons The pons is a structure located on the brain stem. It is cranial to the medulla oblongata, caudal to the midbrain, and ventral to the cerebellum....	Abducens nucleus Abducens nucleus The abducens nucleus is the originating nucleus from which the abducens nerve emerges - a cranial nerve nucleus. This nucleus is located beneath the fourth ventricle in the Anatomical terms of location portion of the pons, Anatomical terms of location to the sulcus limitans....	Innervates the lateral rectus, which abducts the eye; Located in superior orbital fissure Superior orbital fissure The superior orbital fissure is a foramen in the skull, although strictly it is more of a cleft, lying between the Small wings of the sphenoid and Great wings of the sphenoid of the sphenoid bone.... \|- \| VII	Facial nerve Facial nerve The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla oblongata, and controls the muscles of facial expression, and taste to the anterior two-thirds of the tongue....	Both	Pons Pons The pons is a structure located on the brain stem. It is cranial to the medulla oblongata, caudal to the midbrain, and ventral to the cerebellum.... (cerebellopontine angle) above olive	Facial nucleus, Solitary nucleus Solitary nucleus The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial nerve , glossopharyngeal nerve and vagus nerve cranial nerves.... , Superior salivary nucleus Superior salivary nucleus The Superior salivary nucleus of the facial nerve is a visceromotor cranial nerve nucleus located in the pontine tegmentum.Parasympathetic efferent fibers of the facial nerve arise according to some authors from the small cells of the facial nucleus, or according to others from a special nucleus of cells scattered in the reticular formati...	Provides motor innervation to the muscles of facial expression and stapedius Stapedius The stapedius is the smallest skeletal muscle in the human body. At just over one millimeter in length, its purpose is to stabilize the smallest bone in the body, the stapes.... , receives the special sense of taste from the anterior 2/3 of the tongue, and provides secretomotor Secretomotor Secretomotor refers to the capacity of a structure to induce a gland to secrete a substance .Secretomotor nerve endings are frequently contrasted with sensory neuron endings and motor nerve endings.... innervation to the salivary gland Salivary gland The salivary glands in mammals are exocrine glands that produce saliva. They also secrete amylase, an enzyme that breaks down starch into glucose. In other organisms such as Insecta, salivary glands are often used to produce biologically important proteins like silk or glues, and fly salivary glands contain polytene chromosomes that have been usefu... s (except parotid) and the lacrimal gland Lacrimal gland The lacrimal glands are paired almond-shaped glands, one for each eye, that secrete the aqueous layer of the tears film. They are situated in the upper, outer portion of each Orbit .... ; Located and runs through internal acoustic canal to facial canal Facial canal The facial canal is a canal running from the internal acoustic meatus to the stylomastoid foramen, with approximately 3cm total length is the longest osseous canal of a nerve in a man .... and exits at stylomastoid foramen Stylomastoid foramen Between the styloid process and mastoid portion of the temporal bone processes of the temporal bone is the stylomastoid foramenIt is the termination of the facial canal, and transmits the facial nerve and stylomastoid artery.... \|- \| VIII	Vestibulocochlear nerve Vestibulocochlear nerve The vestibulocochlear nerve is the eighth of twelve cranial nerves, and is responsible for transmitting sound and equilibrium information from the inner ear to the brain.... (or auditory-vestibular nerve or statoacustic nerve)	Sensory	Lateral to CN VII (cerebellopontine angle)	Vestibular nuclei Vestibular nuclei The vestibular nuclei are the cranial nuclei for the vestibular nerve.... , Cochlear nuclei Cochlear nuclei The cochlear nuclei consist of:* the dorsal cochlear nucleus, corresponding to the tuberculum acusticum on the dorso-lateral surface of the inferior peduncle; and...	Senses sound, rotation and gravity (essential for balance & movement); Located in internal acoustic canal \|- \| IX	Glossopharyngeal nerve Glossopharyngeal nerve The glossopharyngeal nerve is the ninth of twelve pairs of cranial nerves . It exits the brainstem out from the sides of the upper Medulla oblongata, just rostral to the vagus nerve....	Both	Medulla Medulla Medulla refers to the middle of something, and derives from the Latin word for 'marrow' .In medicine it refers to either bone marrow, the spinal cord, or more generally, the middle part of a structure ....	Nucleus ambiguus Nucleus ambiguus The nucleus ambiguus is a region of histology disparate cell s located just Dorsum to the inferior olivary nucleus in the Human anatomical terms#Anatomical directions portion of the upper medulla oblongata.... , Inferior salivary nucleus, Solitary nucleus Solitary nucleus The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial nerve , glossopharyngeal nerve and vagus nerve cranial nerves....	Receives taste from the posterior 1/3 of the tongue, provides secretomotor innervation to the parotid gland Parotid gland For the toad wart, see parotoid gland.The parotid gland is the largest of the salivary glands. It is found wrapped around the mandibular ramus, and it secretes saliva through Stensen's duct into the oral cavity, to facilitate mastication and swallowing.... , and provides motor innervation to the stylopharyngeus (essential for tactile, pain, and thermal sensation). Some sensation is also relayed to the brain from the palatine tonsils. Sensation is relayed to opposite thalamus and some hypothalamic nuclei. Located in jugular foramen Jugular foramen The jugular foramen, a large aperture in the base of the skull. It is located behind the carotid canal and is formed in front by the petrous portion of the temporal, and behind by the occipital; it is generally larger on the right than on the left side... \|- \| X	Vagus nerve Vagus nerve The vagus nerve is the tenth of twelve paired cranial nerves, and is the only nerve that starts in the brainstem and extends, through the jugular foramen, down below the head , to the neck, chest and abdomen, where it contributes to the innervation of the viscera....	Both	Posterolateral sulcus of Medulla Medulla Medulla refers to the middle of something, and derives from the Latin word for 'marrow' .In medicine it refers to either bone marrow, the spinal cord, or more generally, the middle part of a structure ....	Nucleus ambiguus Nucleus ambiguus The nucleus ambiguus is a region of histology disparate cell s located just Dorsum to the inferior olivary nucleus in the Human anatomical terms#Anatomical directions portion of the upper medulla oblongata.... , Dorsal motor vagal nucleus, Solitary nucleus Solitary nucleus The solitary nucleus and tract are structures in the brainstem that carry and receive visceral sensation and taste from the facial nerve , glossopharyngeal nerve and vagus nerve cranial nerves....	Supplies branchiomotor innervation to most laryngeal and pharyngeal muscles; provides parasympathetic fibers to nearly all thoracic and abdominal viscera down to the splenic flexure Splenic flexure The splenic flexure is a sharp bend between the Transverse colon and the Descending colon Colon in the left upper quadrant of humans. The left colic flexure is near the spleen, and hence called the splenic flexure.... ; and receives the special sense of taste from the epiglottis. A major function: controls muscles for voice and resonance and the soft palate. Symptoms of damage: dysphagia Dysphagia Dysphagia is the medical term for the symptom of difficulty in swallowing. Although classified under "symptoms and signs" in ICD-10, the term is sometimes used as a condition in its own right.... (swallowing problems). Located in jugular foramen Jugular foramen The jugular foramen, a large aperture in the base of the skull. It is located behind the carotid canal and is formed in front by the petrous portion of the temporal, and behind by the occipital; it is generally larger on the right than on the left side... \|- \| XI	Accessory nerve Accessory nerve In anatomy, the accessory nerve is a nerve that controls specific muscles of the neck. As a part of it was formerly believed to originate in the brain, it is considered a cranial nerve.... (or cranial accessory nerve or spinal accessory nerve)	Motor	Cranial and Spinal Roots	Nucleus ambiguus Nucleus ambiguus The nucleus ambiguus is a region of histology disparate cell s located just Dorsum to the inferior olivary nucleus in the Human anatomical terms#Anatomical directions portion of the upper medulla oblongata.... , Spinal accessory nucleus Spinal accessory nucleus The spinal accessory nucleus lies within the cervical spinal cord in the ventral horn. The nucleus ambiguus is classically said to provide the "cranial component" of the accessory nerve....	Controls muscles of the neck and overlaps with functions of the vagus. Examples of symptoms of damage: inability to shrug, weak head movement, velopharyngeal insufficiency; Located in jugular foramen Jugular foramen The jugular foramen, a large aperture in the base of the skull. It is located behind the carotid canal and is formed in front by the petrous portion of the temporal, and behind by the occipital; it is generally larger on the right than on the left side... \|- \| XII	Hypoglossal nerve Hypoglossal nerve The hypoglossal nerve is the twelfth cranial nerve , leading to the tongue. The nerve arises from the hypoglossal nucleus and emerges from the medulla oblongata in the preolivary sulcus separating the olive and the pyramid....	Motor	Medulla Medulla Medulla refers to the middle of something, and derives from the Latin word for 'marrow' .In medicine it refers to either bone marrow, the spinal cord, or more generally, the middle part of a structure ....	Hypoglossal nucleus Hypoglossal nucleus The hypoglossal nucleus is a cranial nerve nucleus, and it extends the length of the medulla, and being a motor nucleus, is close to the midline....	Provides motor innervation to the muscles of the tongue and other glossal muscles. Important for swallowing (bolus formation) and speech articulation. Located in hypoglossal canal Hypoglossal canal The hypoglossal canal is a bony canal in the occipital bone of the skull....

Cranial nerves in non-human vertebrates

Human cranial nerves are evolution

Evolution

In biology, evolution is change in the heritability trait of a population of organisms from one generation to the next. These changes are caused by a combination of three main processes: variation, reproduction, and selection....
arily homologous

Homology (biology)

In evolutionary biology, homology refers to any similarity between characteristics that is due to their common descent. The word homologous derives from the ancient Greek ??????e??, 'to agree'....
to those found in many other vertebrate

Vertebrate

Vertebrates are members of the subphylum Vertebrata, chordates with Vertebras or Vertebral columns. The grouping sometimes includes the hagfish, which have no vertebrae, but are genetically quite closely related to lampreys, which do have vertebrae....
s. Cranial nerves XI and XII evolved in the common ancestor to amniote

Amniote

The amniotes are a group of tetrapod vertebrates that have a terrestrially adapted egg. They include the Synapsida and Sauropsida . Amniote embryos, whether laid as eggs or carried by the female, are protected and aided by several extensive membranes....
s (non-amphibian tetrapods) thus totalling twelve pairs. These characters are synapomorphies for their respective clades. In some primitive cartilagenous fishes, such as the dogfish

Dogfish

Dogfish is a name applied to a number of small sharks found in the northeast Atlantic Ocean, Pacific Ocean, and Mediterranean Sea oceans. It is applied especially to those in the three Family Scyliorhinidae, Dalatiidae, and Squalidae....
(Squalus acanthias), there is a terminal nerve numbered zero (as it exits the brain before the first cranial nerve).

Mnemonic devices

As the list is important to keep in mind during the examination of the nervous system, there are many mnemonic

Mnemonic

A mnemonic device is a memory aid. Commonly met mnemonics are often verbal, something such as a very short poem or a special word used to help a person remember something, particularly lists, but may be visual, kinesthetic or auditory....
devices in circulation to help remember the names and order of the cranial nerves. Because the mind recalls rhymes well, the best mnemonics often use rhyming schemes. One of the best known examples is, "On old Olympus' Towering Tops, a Finn and German viewed some hops".

External links

- University of Toronto
University of Toronto

The University of Toronto is a public university research university in Toronto, Ontario, Canada, situated a mile north of the city's Financial District, Toronto on grounds that surround Queen's Park ....
Medicine*

Cranial nerves

Cranial nerves in non-human vertebrates

Mnemonic devices

See also

External links